[ML] Add override for data which doesn't contain a time field (#147504)

Adds a checkbox to the overrides flyout to allow the user to tell the
find structure endpoint that the data does not contain a time field.


![image](https://user-images.githubusercontent.com/22172091/207582663-a510083e-be75-4ab8-bf7e-c91d72734c6f.png)

If the original analysis of the data does not find a time field, this
checkbox is unchecked by default.

Closes #146700

Also removes the jest snapshot test for the override flyout as it isn't
very useful.

x-pack/plugins/data_visualizer/common/constants.ts

@@ -19,6 +19,8 @@ export const MAX_FILE_SIZE_BYTES = 104857600; // 100MB
 export const ABSOLUTE_MAX_FILE_SIZE_BYTES = 1073741274; // 1GB
 export const FILE_SIZE_DISPLAY_FORMAT = '0,0.[0] b';
 
+export const NO_TIME_FORMAT = 'null';
+
 // Value to use in the Elasticsearch index mapping meta data to identify the
 // index as having been created by the File Data Visualizer.
 export const INDEX_META_DATA_CREATED_BY = 'file-data-visualizer';

x-pack/plugins/data_visualizer/public/application/common/components/utils/utils.ts

@@ -7,7 +7,7 @@
 
 import { isEqual } from 'lodash';
 import type { AnalysisResult, InputOverrides } from '@kbn/file-upload-plugin/common';
-import { MB, FILE_FORMATS } from '../../../../../common/constants';
+import { MB, FILE_FORMATS, NO_TIME_FORMAT } from '../../../../../common/constants';
 
 export const DEFAULT_LINES_TO_SAMPLE = 1000;
 const UPLOAD_SIZE_MB = 5;
@@ -117,10 +117,15 @@ export function createUrlOverrides(overrides: InputOverrides, originalSettings:
 }
 
 export function processResults({ results, overrides }: AnalysisResult) {
-  const timestampFormat =
-    results.java_timestamp_formats !== undefined && results.java_timestamp_formats.length
-      ? results.java_timestamp_formats[0]
-      : undefined;
+  let timestampFormat;
+  if (
+    (overrides && overrides.timestamp_format === NO_TIME_FORMAT) ||
+    results.java_timestamp_formats === undefined
+  ) {
+    timestampFormat = NO_TIME_FORMAT;
+  } else if (results.java_timestamp_formats.length) {
+    timestampFormat = results.java_timestamp_formats[0];
+  }
 
   const linesToSample =
     overrides !== undefined && overrides.lines_to_sample !== undefined